Wood stairs and landing in R2 building

[Mike NY]

Are wood stairs and landings allowed in a R2 type VA building?

We originally spec'd steel and concrete stairs in the stairway shafts but the client is requesting a change to wood. I cannot find a clear answer in the NYS building code.

Building is 4 stories, approx 4,000 sq ft per floor with 2 stairway shafts and 1 elevator. I don't recall ever seeing wood stairs inside a cmu block stair shaft. Is wood OK code wise?

[Jerry Peck - Codeman]

Are wood stairs and landings allowed in a R2 type VA building?

Based on the following key words:
- stairway shafts
- wood stairs inside a cmu block stair shaft

Yes and no. (Or, as AHJ like to say: "It depends.")

This may be why you are not getting clear definitive answers:

- 602.5 Type V. Type V construction is that type of construction in which the structural elements, exterior walls and interior walls are of any materials permitted by this code.
- - 602.5 would say that you can use wood.

- SECTION 1020 VERTICAL EXIT ENCLOSURES
- - 1020.1 Enclosures required. Interior exit stairways and interior exit ramps shall be enclosed with fire barriers constructed in accordance with Section 706 or horizontal assemblies constructed in accordance with Section 711, or both. Exit enclosures shall have a fire-resistance rating of not less than 2 hours where connecting four stories or more and not less than 1 hour where connecting less than four stories. The number of stories connected by the exit enclosure shall include any basements but not any mezzanines. An exit enclosure shall not be used for any purpose other than means of egress.
- - - Exceptions:
- - - - (list of exceptions not included here)

The vertical exit enclosure is required to be rated to 2 hours, unless an exception is met for a lower rating, to provide a minimum of 2 hours for the occupants to escape or be rescued, The stair structure itself in that vertical exit enclosure would, therefore, need to provide the same escape and rescue time (fire rating). So, if the stair itself was constructed of wood, the stair itself would be required to be protected for the same 2 hours, unless an exception is met for a lower rating, and that would be very difficult to do - how would you protect the wood stringers and wood treads to give them a 2 hours rating and yet not hinder in the use of those stairs (maintain required rise, run, etc., requirements)?

Sounds impossible to accomplish.

I always say that "the impossible only takes longer and/or costs more money, but it is *possible* ... just may not have been done ... yet" (possibly for practical reasons).

An example I give is that the Empire State Building *could* be relocated from New York City to Miami with all utilities kept on and the building occupied during the move ... it *could* be done ... with enough money thrown at it - why anyone would want to do that would be the real question.

The same applies here - one *could* construct wood stairs and then protect the wood stairs with a 2 hour rating in a manner in which the protection did not hinder the occupants use of the stairs (maintain required rise, run, etc., requirements) ... it *could* be done - why anyone would want to do that would be the real question.

It would be much more practical, efficient, easier, less costly, etc., to construct the stairs out of concrete or steel. But ... I'm always up for a challenge to accomplish something which seems impossible ... as long as someone else is paying for it.